Test and measurement apparatuses in general, and oscilloscopes in particular, allow a user to view certain aspects of an electronic or other signal. In the case of a traditional digital oscilloscope, the apparatus allows the user to view an electronic signal presented to an input of the oscilloscope. Each oscilloscope is provided with a number of input channels for receiving signals thereon. Furthermore, each oscilloscope is provided with one or more trigger options in order to allow for the indication of starting and stopping the recordation of data. Many oscilloscopes allow for an internally generated trigger, or for an externally provided trigger to be utilized.
While performing a number of tests or the like, a user may wish to view, compare, or test a plurality of signals at one time. While this is what an oscilloscope is designed to do, it may be the case that the user wishes to acquire more signals than there are available inputs in a particular oscilloscope. Traditionally, the user has not been able to do so, and must resort to acquiring some of the signal, storing them, and then acquiring other of the signals. This method, however, is unacceptable for a number of reasons in that it does not allow the viewing of a large number of simultaneously generated signals.
The need for an acquisition system with more than four channels is growing. When employing a channel combining technique, such as LeCroy® DBI technology as described, for example in U.S. Pat. No. 7,219,037, the entire contents thereof being incorporated herein by reference, and other related patents and applications, such multiple channels are particularly advantageous in order to allow for the acquisition of a large number of channels at extremely high bandwidth. The ability to efficiently build such a system as desired by differing users with differing needs also poses substantial difficulty. While it is possible to build a traditional acquisition system with more than 4 channels, before building any such system, one must query how many channels should be included? Some solutions may benefit from up to eight channels while others may require 64 or more channels. Building a traditional static acquisition system having a highest possible number of channels would pose a substantial cost and computing burden on users requiring substantially lower power.
Yield when producing such a system may also be a problem. Building an acquisition system with channel bandwidth in excess of 15 GHz can be very difficult. Inconsistencies in manufacturing processes may require one or two amplifiers to be changed in a system with only four channels. Producing a 64 channel system may prove to be nearly impossible to properly assemble. Testing requirements would also be difficult and time consuming, requiring complete retesting each time any single amplifier or other critical component was switched out.
Finally, power requirements of such a system are also of concern. Acquisition systems with more than 15 GHz of bandwidth are power hungry. Building a system with more than 4 channels would require extremely complex cooling techniques that would be nearly impossible to manage. Also from a customer point of view a power cord for such a unit would require a large current capacity. Such a requirement is not user friendly, likely requiring an unconventional connector, therefore requiring electrical rewiring in order to support the load and use the system.
Therefore it would be beneficial to provide an improved method and apparatus that overcomes the drawbacks of the prior art, and avoids the problems associated with building an acquisition system with a large number of channels.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification and the drawings.